Machine for polishing, sanding, and the like



Jan. 12, 1937. w. o. ARNOLD 2,057,624

MACHINE FOR POLISHING, SANDING AND THE LIKE Filed July 18, 19155 2Sheets-Sheet l INVENTOR. J1 4 iv Maxim; flA/wald ATTORNEY.

Jan. 12, 1937. w Q ARNOLD 2,067,624

MACHINE FOR POLISHING, SANDING AND THE LIKE Filed July 18, 1935 2Sheets-Sheet 2 TEE- db A A A INVENTOR.

ATTORNEY.

J7 J3 fl .7. Jz T15 Patented Jan. 12, 1937 UNITED STATES PATENT OFFICEMACHINE FOR POLISHING, SANDING, AND THE LIKE 10 Claims.

This invention relates to improvements in machines for polishing,sanding and the like.

Among the principal objects which the present invention has in view are:To provide an im- 5 proved machine as characterized, having meanswhereby the machine can be used for a plurality of purposes; to providemeans for operating the same at a minimum cost; to be enabled to adjustworkable parts of the machine without too much delay; to be enabled touse the machine as a sander and/or a rubber; to provide means when usedas a sander whereby sandpaper or the like can be readily attached and/orremoved in minimum time; to be enabled to employ a double re- 15ciprocating means for operating the machine; to grip the sandpaper orthe like at the ends thereof which are transverse to direction ofmovement; to hold the sandpaper or the like under tension and take upslack therein while in use; to obtain 20 straight-line reciprocation ofthe rubbing and/or sanding element; to reduce to substantial eliminationthe undesired vibration of the machine; to lubricate the moving parts inuse by an application of the lubricant at one place; to spread the 25exhaust air or other fluid actuating medium; to reduce to a minimum theworking parts and to otherwise simplify the construction and use of myimproved machine; and to obtain other advantages and resultsas may bebrought out in 30 the following description.

Drawings:

Figure l is a View in elevation, looking at what may, for convenience,be termed the front of my improved machine;

35 Figure 2 is a vertical sectional view, looking in the same directionas Figure 1, and shown as taken on line 22 of Figure 3;

Figure 3 is an end elevation;

Figures 4 and 5 are transverse vertical sectional 40 views taken onlines 4-4 of Figure 2 and 5-5 of Figure 1, respectively;

Figure 6 is a plan of the synchronizing connection for the reciprocatingplatens; and

Figure 7 is a View similar to Figure 2 and show- 45 ing the adaptabilityof a sanding tool thereon.

Description:

As seen in the drawings, the reference numeral l indicates the machinehousing or body having therein a pair of opposed cylinders H, I I, and

50 which may, for convenience, comprise a single boring so that saidcylinders are in direct communication with each other at their innerends. In each cylinder H is a piston l2, and the two pistons are opposedwith respect to each other,

55 each with a piston rod [3, shown integral therewith, projecting fromthe outer end of the cylinder in which such piston operates.

At the. outer end of each piston rod I 3 is mounted a coupling It thelower part of which interlocks with and supports a slide l5, these partsbeing shown secured rigidly together by bolts IS. The slide i5 extendspartway beneath the body or housing l 0, parallel to the axis of thepiston l2 and piston rod I 3. The inter-engaging surfaces between saidslide and the housing are prefer- 10 ably provided with serrations i5longitudinally disposed in direction of sliding so as to prevent anylateral vibration and to provide a good support and sliding contact. Thesame serrations in the slide may extend to the outer end thereof ifdesired and, with similar serrations in the bottom of coupling l4,provide an aligning, nontwisting connection between the slide l5 andcoupling l4.

Fluid pressure, such as air, is shown introduced through a suitablecoupling A at the top of the housing communicating with a horizontalchannel I! in the housing so as to enter through ports i8 next to theouter ends of the cylinders H, H between the outer face of the pistonsl2 and appropriate packing I 9. There will consequently always besufiicient pressure on the outer ends of the pistons to actuate thepistons inwardly when there is no applied pressure at the opposite sideof pistons. In the piston rods I 3, I provide one or more radial valveports 20, which, for most of the stroke, are covered by the packing 19,but which, at the inner stroke position of the pistons will be exposedwithin the cylinders H to receive the pressure communicated theretothrough channel I? and ports I 8, l8. The pistons likewise havelongitudinal passages 2| therein in constant communication with radialvalve ports 20 and opening through the inner ends of the piston. By thiscourse pressure will be introduced to the inner ends of the cylindersand by virtue of that pressure acting upon the entire inner ends of thepistons, the pistons are thereupon both forced outwardly to a positionwhere the inner ends thereof uncover exhaust ports 22 opening downwardlytoward the slides l5. By this means, an automatically reversingreciprocating motion is imparted to the pistons, piston rods, couplingsand slides.

In order to synchronize the movement of the two slides l5 under workingconditions, each is preferably provided with a rack 23 extending in adirection longitudinally of the direction of sliding motion of theslides. The racks of the two slides are offset with respect to eachother so as to overlap with a space between sufficient to receive anidler gear or pinion 25 in mesh with both racks. This constructionnecessitates that both slides must move substantially simultaneously inopposite directions and change their direction of movement substantiallysimultaneously. The pinion is shown as mounted upon the lower end ofcoupling A as a pivot. Furthermore, the pinion, as well as the racks andinner ends of the slides are shown held upwardly in place toward thehousing by U-shaped brackets 2% extending longitudinally of the housingand slides and fixed to the housing as by bolts 26.

The slides l as here shown, provide integrally formed flanges 2'!extending laterally from oppo site sides thereof next the bottom of theslides so as to constitute what may here be termed a platen. The workingtool to be Operated by the machine is attached against the undersideofthe platen. The two tools will be operated simultaneously toward eachother and simultaneously away from each other thereby reducing vibrationof the body of the machine to a minimum.

It is a feature of the present invention to provide proper lubricatingmeans for all of the working parts and enable the lubricant to beinjected only at one place by the operator. As here shown, a one-waylubricating fitting 28 is shown at one side of the housing. Details ofthis fitting are well known in the art, they being constructed to admitlubricant from the exterior, but having a one-way ball valve meanstherein for preventing return of the lubricant or other pressure fromescaping. Such a fitting is here employed and shown particularly inFigure 5 as entering the air conveying passages at the juncture of themain channel ll with coupling A where the pas sage through the couplingopens into said channel. It may accordingly be here noted that thecoupling A, in the part extending from channel l'l downwardly to its endforming the pivot for pinion 2i has a lubricant duct 29 thereinsubstantially to its lower end where a transverse oil hole 30 radiallyof the fitting will permit grease or other lubricant to pass from theduct to the surface between the fitting and pinion. The lubricantintroduced into the main channel il will be carried by the operating airor other fluid into the cylinders: II for lubricating the pistons, andsome will be carried out of the exhaust port 22. Preferably the exhaustport 22, at the exhaust period, registers with a transverse slot M inthe upper face of the slide l5. This slot 35 is transverse to theseveral serrations in the upper face of the slide, and preferably thepeaks of the ridges of the serrations in both the housing and slide arerounded off or otherwise shaped so as to provide space. between theridges of the serrations and the juxtaposed valleys thereof. The exhaustfluid pressure will therefore spread laterally in slot SI and thenescape through the several spaces longitudinally of the serrations.Lubricant is carried with this exhaust air and accordingly maintains thedesired lubricated condition between the slide and the housing.

According to the present invention, I may provide a buifing tool 32 tobe secured to the aforesaid platen or underside of the flanges Zl. Thistool is shown as providing a plate 33 on the underside of which is heldbuffing material such as a felt pad 34. The pad is preferably secured tothe plate by means of depressed nuts 35 in the pad, receiving screws 36projecting into the pad from said plate 33. The tool is secured flatwiseagainst flanges 21 of the platen by suitable bolts 31.

Another tool 38 more especially intended for mounting sheet abrasive,such as sand-paper is shown in Figure 7 attached to the flanges 2'! ofthe platen by said bolts 31. This tool preferably provides a lower plate39 as a bearing surface for the sheet of abrasive Ml. Upstanding sideflanges 4i space this plate 39 from the flanges 21 of the platen andprovide means for receiving the attaching bolts 31. Between said lowerplate and the platen and at the opposite ends of the tool which in useare transverse to the direction of movement of the tool are jaws 42.These jaws may conveniently provide one member 43 pivoted at it to theupstanding flange ll. The other jaw member a5 is pivoted as at 46 to thefirst said jaw member and has associated in fixed relationto the saidother jaw member 45 an upwardly projecting crank arm M. From the upperend of this crank arm 41 extends a rod 48 projecting toward the middleof the tool and having a nut 39 at its inner end. Near the pivoted endof this rod 48 the same passes through a yoke 5! or similar part of aneccentric bar 52 extending substantially parallel to the rod 48. Acompression spring 53 is upon the rod and bears at its ends against nut49 and yoke 5|. An eccentric 54 operated by a screw-head 55 at theoutside of flange 4! will move eccentric bar 52 longitudinally therebyeither tensioning the spring or releasing the tension thereof dependingupon the turning of the eccentric and screw-head. When the spring isplaced under pressure, it tends to close the jaw members together togrip the abrasive sheet and likewise tends to swing the jaws upwardly asa unit, thereby placing tension on the sheet. This tension is in thelongitudinal direction of the sheet corresponding to the direction ofmovement to which the sheet is subjected in the operation of themachine. It will be seen that replacement of the abrasive sheet and tensioning of the same is accomplished with the greatest of ease and isunder the simple control of the screw-head 55.

It will furthermore be understood that by virtue of the guidingserrations between the body of the machine and the slides, that therewill be no lateral deviation of the direction of movement of theparticular tool employed. This lends itself to enabling the tool to beused for producing a very smooth and high polish. Furthermore, the

straight-line reciprocation of the tools with both tools acting inalinement, enables the same to be used upon surfaces which arelongitudinally regular but transversely irregular, such as mouldings.The face of the tool toward the work when of such irregular character,may be shaped, as will be understood, to agree with the shape of thesurface being acted upon.

I claim:

1. A machine as characterized comprising a housing providing a singleboring the ends of which constitute opposed cylinders, each of saidcylinders having a piston and a piston rod, a

coupling mounted at the outer end of each of which constitute opposedcylinders, each of said cylinders having a piston and a piston rod, eachof said piston rods at their outer ends having a connecting meansmounted thereon, a pair of slides underneath said housing, each slidebeing beneath its respective piston and made fast with respect to thesaid piston rods by said connecting means for obtaining in said slides adouble reciprocating motion, and inter-engaging means between saidslides adapted to synchronize operation of the said slides in opposeddirections, and means on the underside of said slides for each mountinga tool thereon.

3. A machine as characterized comprising a housing providing a singleboring the ends of which constitute opposed cylinders, each of saidcylinders having a piston and a piston rod, each of said piston rods attheir outer ends having a connecting means mounted thereon, a pair ofslides underneath said housing, each slide being beneath its respectivepiston and made fast with respect to the said piston rods by saidconnecting means for obtaining in said slides a double reciprocatingmotion, and a pinion meshing with respect to both slides adapted tosynchronize operation of the slides in opposed directions, and means onthe underside of said slides for each mounting a tool thereon.

4. A machine as characterized comprising a housing providing a singleboring the ends of which constitute opposed cylinders, each of saidcylinders having a piston and a piston rod, each of said piston rods attheir outer ends having a connecting means mounted thereon, a pair ofslides underneath said housing, each slide being beneath its respectivepiston and made fast With respect to the said piston rods by saidconnecting means for obtaining in said slides a double reciprocatingmotion, a pair of overlapping racks one on each of said slides, and apinion between and meshing with said racks adapted to synchronizeoperation of the slides in opposed directions, and means on theunderside of said slides for each mounting a tool thereon.

5. A machine as characterized comprising a housing providing a singleboring the ends of which constitute opposed cylinders, each of saidcylinders having a piston and a piston rod, each of said piston rods attheir outer ends having a connecting means mounted thereon, a pair ofslides underneath said housing, each slide being beneath its respectivepiston and made fast with respect to the said piston rods by saidconnecting means for obtaining in said slides a double reciprocatingmotion, and a pinion meshing with respect to both slides adapted tosynchronize operation of the slides in opposed directions, and means onthe underside of said slides for each mounting a tool thereon, andbrackets for supporting the inner ends of the slides maintaining thesame in alinement and in sliding contact with the housing.

6. A machine as characterized comprising a housing providing a singleboring the ends of which constitute opposed cylinders, each of saidcylinders having a piston and a piston rod, each of said piston rods attheir outer ends having a connecting means mounted thereon, a pair ofslides underneath said housing, each slide being beneath its respectivepiston and made fast with respect to the said piston rods by saidconnecting means for obtaining in said slides a double reciprocatingmotion, a pair of overlapping racks one on each of said slides, and apinion between and meshing with said racks adapted to synchronizeoperation of the slides in opposed directions, and means on theunderside of said slides for each mounting a tool thereon, and bracketsfor supporting the pinion and the inner ends of the slides maintainingthe same in alinement and in sliding contact with the housing.

7. A machine as characterized comprising a housing having a fluidactuated piston, and a slide next the housing for impartingreciprocation to a tool and the like from reciprocation of the piston,said slide and housing providing longitudinal inter-engaging serrationsfor guiding and receiving pressure of the slide with respect to thehousing, said housing providing means for discharging the exhaust fromthe actuation of the piston between the serrations of the slide andhousing.

8. A machine as characterized comprising a housing having a fluidactuated piston, and a slide next the housing for impartingreciprocation to a tool and the like from reciprocation of the piston,said slide and housing having bearing surfaces and interveningnon-bearing surfaces, said housing providing means for discharging theexhaust from the actuation of the piston between the nonbearing surfacesof the slide and housing, and means for introducing lubricant into theactuating fluid for the piston and thereby lubricate both the piston andthe bearing surface of sliding contact between the slide and housing.

9. A machine as characterized comprising a housing having a fluidactuated piston, and a slide next the housing for impartingreciprocation to a tool and the like from reciprocation of the piston,said slide and housing providing longitudinal interengaging serrationsfor guiding and receiving pressure of the slide with respect to thehousing, and means for introducing lubricant into the actuating fluidfor the piston and passing it through said serrations therebylubricating both the piston and the surface of sliding contact betweenthe slide and housing.

10. A machine as characterized comprising a housing having a fluidactuated piston, and a slide next the housing for impartingreciprocation to a tool and the like from reciprocation of the piston,said slide and housing providing longitudinal inter-engaging serrationsfor guiding and receiving pressure of the slide with respect to thehousing, said housing providing means for discharging the exhaust fromthe actuation of the piston between the slide and housing through saidserrations, and means for introducing lubricant into the actuating fluidfor the piston and thereby lubricate both the piston and the surface ofsliding contact between the slide and housing.

WILLIAM O. ARNOLD.

